1. Field of the Invention
This invention relates to a shutter device for a camera of the kind having a plurality of shutter blades and to the camera having the shutter device of this kind.
2. Description of the Related Art
The conventional shutter device for a camera has been arranged as shown in FIGS. 11 and 12. Referring to these figures, the shutter device comprises shutter blades 401 and 402, a blade retaining plate 403 in which an aperture part 403a is formed to give a maximum aperture diameter, a shutter base plate 404, and a driving pin 405 which is arranged to be caused to drive the shutter in the direction of arrow E by a known driving device.
The shutter blades 401 and 402 respectively have holes 401a and 402a rotatably fitted on fulcrum pins 404a and 404b which are provided on the shutter base plate 404. The driving pin 405 is slidably fitted into slots 401b and 402b which are respectively formed in the shutter blades 401 and 402. The blade retaining plate 403 is mounted on the shutter base plate 404 by screws (not shown) or an adhesive or the like with some clearance left between them in such a way as to allow the shutter blades 401 and 402 to turn respectively around the fulcrum pins 404a and 404b. The shutter blades 401 and 402 are thus arranged to be caused to turn by the movement of the driving pin 405 in the direction of arrow E in such a way as to form an aperture or to close the aperture.
FIG. 12 shows in a plan view the shutter blades 401 and 402 in relation to the aperture part 403a. The illustration shows the shutter blades 401 and 402 in their positions closing the aperture part 403a.
In order to perfectly prevent the film from being exposed to light with the aperture part 403a closed by the shutter blades 401 and 402, the shutter blades 401 and 402 must be arranged to be adequately overlapping the blade retaining plate 403 (a dimension "b" shown in FIG. 12) and also to adequately overlap each other (a dimension "a" shown in FIG. 12). However, clearances are provided in accordance with the conventional arrangement between the shutter base plate 404, the shutter blade 401, the shutter blade 402 and the blade retaining plate 403 for smooth rotation of the shutter blades. To prevent external light from coming round through these clearances to the surface of the film, therefore, the mutual overlapping amount of the shutter blades 401 and 402 (the dimension "a") and the overlapping amount of the blade retaining plate 403 and the shutter blades 401 and 402 (the dimension "b") must be arranged to be sufficiently large. These large overlapping amounts, however, have been impedimental to a reduction in size of the shutter device.